Kevin starts counting at 40, and he counts by fours. If 40 is the 1st number that Kevin counts. what is the 9th number that he counts?
Explanation: What is the first number that he counts? $40$ What is the second number that he counts? $\begin{align*}&40 + 4 \\ &= 44\end{align*}$ What is the third number that he counts? $\begin{align*}&40 + 4 + 4 \\ &= 40 + (2 \times 4) \\ &= 48\end{align*}$ What is the 9th number that he counts? $\begin{align*}&40 + (8\times4) \\ &= 40 + 32 \\ &= 72\end{align*}$